in acpica/tbfadt.c [439:628]
static void acpi_tb_convert_fadt(void)
{
const char *name;
struct acpi_generic_address *address64;
u32 address32;
u8 length;
u8 flags;
u32 i;
/*
* For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which
* should be zero are indeed zero. This will workaround BIOSs that
* inadvertently place values in these fields.
*
* The ACPI 1.0 reserved fields that will be zeroed are the bytes located
* at offset 45, 55, 95, and the word located at offset 109, 110.
*
* Note: The FADT revision value is unreliable. Only the length can be
* trusted.
*/
if (acpi_gbl_FADT.header.length <= ACPI_FADT_V2_SIZE) {
acpi_gbl_FADT.preferred_profile = 0;
acpi_gbl_FADT.pstate_control = 0;
acpi_gbl_FADT.cst_control = 0;
acpi_gbl_FADT.boot_flags = 0;
}
/*
* Now we can update the local FADT length to the length of the
* current FADT version as defined by the ACPI specification.
* Thus, we will have a common FADT internally.
*/
acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
/*
* Expand the 32-bit DSDT addresses to 64-bit as necessary.
* Later ACPICA code will always use the X 64-bit field.
*/
acpi_gbl_FADT.Xdsdt = acpi_tb_select_address("DSDT",
acpi_gbl_FADT.dsdt,
acpi_gbl_FADT.Xdsdt);
/* If Hardware Reduced flag is set, we are all done */
if (acpi_gbl_reduced_hardware) {
return;
}
/* Examine all of the 64-bit extended address fields (X fields) */
for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
/*
* Get the 32-bit and 64-bit addresses, as well as the register
* length and register name.
*/
address32 = *ACPI_ADD_PTR(u32,
&acpi_gbl_FADT,
fadt_info_table[i].address32);
address64 = ACPI_ADD_PTR(struct acpi_generic_address,
&acpi_gbl_FADT,
fadt_info_table[i].address64);
length = *ACPI_ADD_PTR(u8,
&acpi_gbl_FADT,
fadt_info_table[i].length);
name = fadt_info_table[i].name;
flags = fadt_info_table[i].flags;
/*
* Expand the ACPI 1.0 32-bit addresses to the ACPI 2.0 64-bit "X"
* generic address structures as necessary. Later code will always use
* the 64-bit address structures.
*
* November 2013:
* Now always use the 64-bit address if it is valid (non-zero), in
* accordance with the ACPI specification which states that a 64-bit
* address supersedes the 32-bit version. This behavior can be
* overridden by the acpi_gbl_use32_bit_fadt_addresses flag.
*
* During 64-bit address construction and verification,
* these cases are handled:
*
* Address32 zero, Address64 [don't care] - Use Address64
*
* No override: if acpi_gbl_use32_bit_fadt_addresses is FALSE, and:
* Address32 non-zero, Address64 zero - Copy/use Address32
* Address32 non-zero == Address64 non-zero - Use Address64
* Address32 non-zero != Address64 non-zero - Warning, use Address64
*
* Override: if acpi_gbl_use32_bit_fadt_addresses is TRUE, and:
* Address32 non-zero, Address64 zero - Copy/use Address32
* Address32 non-zero == Address64 non-zero - Copy/use Address32
* Address32 non-zero != Address64 non-zero - Warning, copy/use Address32
*
* Note: space_id is always I/O for 32-bit legacy address fields
*/
if (address32) {
if (address64->address) {
if (address64->address != (u64)address32) {
/* Address mismatch */
ACPI_BIOS_WARNING((AE_INFO,
"32/64X address mismatch in FADT/%s: "
"0x%8.8X/0x%8.8X%8.8X, using %u-bit address",
name, address32,
ACPI_FORMAT_UINT64
(address64->address),
acpi_gbl_use32_bit_fadt_addresses
? 32 : 64));
}
/*
* For each extended field, check for length mismatch
* between the legacy length field and the corresponding
* 64-bit X length field.
* Note: If the legacy length field is > 0xFF bits, ignore
* this check. (GPE registers can be larger than the
* 64-bit GAS structure can accommodate, 0xFF bits).
*/
if ((ACPI_MUL_8(length) <= ACPI_UINT8_MAX) &&
(address64->bit_width !=
ACPI_MUL_8(length))) {
ACPI_BIOS_WARNING((AE_INFO,
"32/64X length mismatch in FADT/%s: %u/%u",
name,
ACPI_MUL_8(length),
address64->
bit_width));
}
}
/*
* Hardware register access code always uses the 64-bit fields.
* So if the 64-bit field is zero or is to be overridden,
* initialize it with the 32-bit fields.
* Note that when the 32-bit address favor is specified, the
* 64-bit fields are always re-initialized so that
* access_size/bit_width/bit_offset fields can be correctly
* configured to the values to trigger a 32-bit compatible
* access mode in the hardware register access code.
*/
if (!address64->address
|| acpi_gbl_use32_bit_fadt_addresses) {
acpi_tb_init_generic_address(address64,
ACPI_ADR_SPACE_SYSTEM_IO,
length,
(u64)address32,
name, flags);
}
}
if (fadt_info_table[i].flags & ACPI_FADT_REQUIRED) {
/*
* Field is required (Pm1a_event, Pm1a_control).
* Both the address and length must be non-zero.
*/
if (!address64->address || !length) {
ACPI_BIOS_ERROR((AE_INFO,
"Required FADT field %s has zero address and/or length: "
"0x%8.8X%8.8X/0x%X",
name,
ACPI_FORMAT_UINT64(address64->
address),
length));
}
} else if (fadt_info_table[i].flags & ACPI_FADT_SEPARATE_LENGTH) {
/*
* Field is optional (Pm2_control, GPE0, GPE1) AND has its own
* length field. If present, both the address and length must
* be valid.
*/
if ((address64->address && !length) ||
(!address64->address && length)) {
ACPI_BIOS_WARNING((AE_INFO,
"Optional FADT field %s has valid %s but zero %s: "
"0x%8.8X%8.8X/0x%X", name,
(length ? "Length" :
"Address"),
(length ? "Address" :
"Length"),
ACPI_FORMAT_UINT64
(address64->address),
length));
}
}
}
}